Satellite-based telemetry consists of placing a backpack with a radio transmitter to a wild bird and tracking the emitted signals to map its daily movements. In Bangladesh, migratory birds stop over every year on their journeys along the ‘Central Asian Flyway’ and the ‘East Asian-Australian Flyway’. Scientific evidence suggests that wild birds can be asymptomatic carriers of numerous avian influenza viruses.

Migratory birds have often been blamed for the spread of highly pathogenic avian influenza (H5N1 HPAI), which, since 2003, has caused mortality and morbidity in animals and humans across Asia, Africa, and Europe. To further investigate the role wild birds’ play in disease transmission dynamics, the government of Bangladesh has agreed to place nine satellite transmitters on migratory birds to track their local movements, as well as their long transcontinental routes.

The project selected specific avian species that travel the longest distance routes, for example from the Arctic to Bangladesh via Mongolia and the Himalayas. This year, it is planned that additional birds will be fitted with transmitters before the migration season starts. At present, it has been estimated that some 477 species of local and migratory birds reside in Bangladesh; of them 301 are thought to be resident species and 176 migratory species.

The tagged birds are tested for avian influenza exposure or infections through blood and fecal samples before they are returned to their natural habitats. The data gathered will be used to assess the flight patterns including altitude, routes and duration of flights as well as the time spent at each location along their flyways. During their lengthy sojourns, birds will be continuously monitored to determine survival rates and retrospective correlation of stopover sites with reported disease outbreaks. This way, objective and verifiable evidence will be available to further elucidate whether migratory birds play a role in the spread of H5N1 HPAI, and if they pose a transmission and infection risk to domestic bird populations along their migratory paths.